<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    /* .box {
      width: 200px;
      height: 200px;
      background-color: #000000;
    } */
  </style>
</head>
<body>
  <div id = "app">
    <!-- {{msg}} -->
    <div class="box" :style="{ width: '1000px',height:'50px','background-color':'#000000','border-radius':'50px'}">
        <div class="inner" :style="{width: precent+'%',height:'50px','background-color':'#6d99d2','border-radius':'50px'}">  
        </div> 
        <span :style="{'margin-left':precent+'%','margin-top':'5px'}">{{precent}}%</span>
    </div> 
   
   <div style="margin-top: 30px;">
    <button @click="precent=25">设置25%</button>
    <button @click="precent=50">设置50%</button>
    <button @click="precent=75">设置75%</button>
    <button @click="precent=100">设置100%</button>
   </div>
  </div>

</body>

<script src="js/vue.js"></script>
<script>
  const app = new Vue({
    el:'#app',
    data:{
      msg:'hello world',
      precent:0,
    },
    methods:{

    }
  })
</script>
</html>